giúp mik vs

a)\(\frac{-5}{-54}\)và\(\frac{11}{72}\)

\(\frac{-5}{-54}=\frac{5}{54}=\frac{5\times4}{54\times4}=\frac{20}{216}\)

\(\frac{11}{72}=\frac{11\times3}{72\times3}=\frac{33}{216}\)

Do : \(\frac{20}{216}< \frac{33}{216}\)

\(\Rightarrow\frac{-5}{-54}< \frac{11}{72}\)

b)\(\frac{-3}{40}\)và\(\frac{7}{-54}\)

\(\frac{-3}{40}=\frac{-3.27}{40.27}=\frac{-81}{1080}\)

\(\frac{7}{-54}=\frac{7.\left(-20\right)}{-54.\left(-20\right)}=\frac{-140}{1080}\)

Do " \(\frac{-81}{1080}>\frac{-140}{1080}\)

\(\Rightarrow\frac{-3}{40}>\frac{7}{-54}\)

#H

-1911-(1234-1911)

 = -1911 + 1234 + 1911

= -1911 + 1911 + 1234

=          0 + 1234

=             1234

GIÚP MIK NHA CÁC BẠN

\(Ư\left(-16\right)\in\)\(\left\{1;-1;2;-2;4;-4;8;-8\right\}\)

Tổng tất cả các ước nguyên không vượt quá 8 của (-16) là:

1 + (-1) + 2 + (-2) + 4 + (-4) + 8 + (-8) = 0

các bạn giúp mik vs

\(\left(-216\right):9+7^5:7^3-\left(-4\right)^2.5\)

\(\Leftrightarrow\left(-24\right)+7^2-16\)

\(\Leftrightarrow\left(-24\right)+49-16\)

\(\Leftrightarrow25-16\)

\(\Leftrightarrow9\)

\(\frac{7}{3a^2}\)và  \(\frac{11b}{5ac}\)( Mẫu chung: \(15a^2c\))

Ta có: \(\frac{7}{3a^2}=\frac{7\cdot5c}{15a^2c}=\frac{35c}{15a^2c};\frac{11b}{5ac}=\frac{11b\cdot3a}{15a^2c}=\frac{33ab}{15a^2c}\)

CHÚC BẠN HỌC TỐT!

\(A=\frac{\frac{4}{17}-\frac{4}{45}+\frac{1}{39}}{\frac{3}{17}-\frac{1}{15}+\frac{1}{52}}=\frac{\frac{4}{3}\left(\frac{4}{17}\cdot\frac{3}{4}-\frac{4}{45}\cdot\frac{3}{4}+\frac{1}{39}\cdot\frac{3}{4}\right)}{\frac{3}{17}-\frac{1}{15}+\frac{1}{52}}\)

\(A=\frac{\frac{4}{3}\left(\frac{3}{17}-\frac{1}{15}+\frac{1}{52}\right)}{\frac{3}{17}-\frac{1}{15}+\frac{1}{52}}=\frac{4}{3}\)

CHÚC BẠN HỌC TỐT!